Question: Do you have loose wooden beads laying around. To few to really be useful?
Question: Do you have leatherstraps. Rather thin?
Question: Do you have friends or family that love to read?
I have the answer for you!
Take a leatherstrap approxiametley 25 cm long.
Make a knot in one end.
Slip on a big bead (1 cm...)
Slip on a smaller bead.
Slip on a third smaller bead.
Make a knot in the other end.
Now you have three beads on a string. Simply arrange them. Two in one end, and one in the other and you have the best bookslip ever. It won't damage the back of the books and it's easy enough for a three year old to make for granny with a little help and some patience (and I know that's not what 3-year olds are known for).
One can always complete the gift with a book if one can afford it.
Didn't really know where to post this, so I put where the beads are most likely to be